1 /* 2 * Copyright (C) 2005, 2007, 2008 Apple Inc. All rights reserved. 3 * 4 * This library is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU Library General Public 6 * License as published by the Free Software Foundation; either 7 * version 2 of the License, or (at your option) any later version. 8 * 9 * This library is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * Library General Public License for more details. 13 * 14 * You should have received a copy of the GNU Library General Public License 15 * along with this library; see the file COPYING.LIB. If not, write to 16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 17 * Boston, MA 02110-1301, USA. 18 * 19 */ 20 21 #ifndef PropertySlot_h 22 #define PropertySlot_h 23 24 #include "Identifier.h" 25 #include "JSValue.h" 26 #include "Register.h" 27 #include <wtf/Assertions.h> 28 #include <wtf/NotFound.h> 29 30 namespace JSC { 31 32 class ExecState; 33 class JSObject; 34 35 #define JSC_VALUE_SLOT_MARKER 0 36 #define JSC_REGISTER_SLOT_MARKER reinterpret_cast<GetValueFunc>(1) 37 38 class PropertySlot { 39 public: 40 PropertySlot() 41 { 42 clearBase(); 43 clearOffset(); 44 clearValue(); 45 } 46 47 explicit PropertySlot(const JSValue base) 48 : m_slotBase(base) 49 { 50 clearOffset(); 51 clearValue(); 52 } 53 54 typedef JSValue (*GetValueFunc)(ExecState*, const Identifier&, const PropertySlot&); 55 56 JSValue getValue(ExecState* exec, const Identifier& propertyName) const 57 { 58 if (m_getValue == JSC_VALUE_SLOT_MARKER) 59 return *m_data.valueSlot; 60 if (m_getValue == JSC_REGISTER_SLOT_MARKER) 61 return (*m_data.registerSlot).jsValue(); 62 return m_getValue(exec, propertyName, *this); 63 } 64 65 JSValue getValue(ExecState* exec, unsigned propertyName) const 66 { 67 if (m_getValue == JSC_VALUE_SLOT_MARKER) 68 return *m_data.valueSlot; 69 if (m_getValue == JSC_REGISTER_SLOT_MARKER) 70 return (*m_data.registerSlot).jsValue(); 71 return m_getValue(exec, Identifier::from(exec, propertyName), *this); 72 } 73 74 bool isCacheable() const { return m_offset != WTF::notFound; } 75 size_t cachedOffset() const 76 { 77 ASSERT(isCacheable()); 78 return m_offset; 79 } 80 81 void setValueSlot(JSValue* valueSlot) 82 { 83 ASSERT(valueSlot); 84 clearBase(); 85 clearOffset(); 86 m_getValue = JSC_VALUE_SLOT_MARKER; 87 m_data.valueSlot = valueSlot; 88 } 89 90 void setValueSlot(JSValue slotBase, JSValue* valueSlot) 91 { 92 ASSERT(valueSlot); 93 m_getValue = JSC_VALUE_SLOT_MARKER; 94 m_slotBase = slotBase; 95 m_data.valueSlot = valueSlot; 96 } 97 98 void setValueSlot(JSValue slotBase, JSValue* valueSlot, size_t offset) 99 { 100 ASSERT(valueSlot); 101 m_getValue = JSC_VALUE_SLOT_MARKER; 102 m_slotBase = slotBase; 103 m_data.valueSlot = valueSlot; 104 m_offset = offset; 105 } 106 107 void setValue(JSValue value) 108 { 109 ASSERT(value); 110 clearBase(); 111 clearOffset(); 112 m_getValue = JSC_VALUE_SLOT_MARKER; 113 m_value = value; 114 m_data.valueSlot = &m_value; 115 } 116 117 void setRegisterSlot(Register* registerSlot) 118 { 119 ASSERT(registerSlot); 120 clearBase(); 121 clearOffset(); 122 m_getValue = JSC_REGISTER_SLOT_MARKER; 123 m_data.registerSlot = registerSlot; 124 } 125 126 void setCustom(JSValue slotBase, GetValueFunc getValue) 127 { 128 ASSERT(slotBase); 129 ASSERT(getValue); 130 m_getValue = getValue; 131 m_slotBase = slotBase; 132 } 133 134 void setCustomIndex(JSValue slotBase, unsigned index, GetValueFunc getValue) 135 { 136 ASSERT(slotBase); 137 ASSERT(getValue); 138 m_getValue = getValue; 139 m_slotBase = slotBase; 140 m_data.index = index; 141 } 142 143 void setGetterSlot(JSObject* getterFunc) 144 { 145 ASSERT(getterFunc); 146 m_getValue = functionGetter; 147 m_data.getterFunc = getterFunc; 148 } 149 150 void setUndefined() 151 { 152 setValue(jsUndefined()); 153 } 154 155 JSValue slotBase() const 156 { 157 return m_slotBase; 158 } 159 160 void setBase(JSValue base) 161 { 162 ASSERT(m_slotBase); 163 ASSERT(base); 164 m_slotBase = base; 165 } 166 167 void clearBase() 168 { 169 #ifndef NDEBUG 170 m_slotBase = JSValue(); 171 #endif 172 } 173 174 void clearValue() 175 { 176 #ifndef NDEBUG 177 m_value = JSValue(); 178 #endif 179 } 180 181 void clearOffset() 182 { 183 // Clear offset even in release builds, in case this PropertySlot has been used before. 184 // (For other data members, we don't need to clear anything because reuse would meaningfully overwrite them.) 185 m_offset = WTF::notFound; 186 } 187 188 unsigned index() const { return m_data.index; } 189 190 private: 191 static JSValue functionGetter(ExecState*, const Identifier&, const PropertySlot&); 192 193 GetValueFunc m_getValue; 194 195 JSValue m_slotBase; 196 union { 197 JSObject* getterFunc; 198 JSValue* valueSlot; 199 Register* registerSlot; 200 unsigned index; 201 } m_data; 202 203 JSValue m_value; 204 205 size_t m_offset; 206 }; 207 208 } // namespace JSC 209 210 #endif // PropertySlot_h 211
